Checklist » Polygonaceae » Polygonum ramosissimum ssp. ramosissimum
Polygonum ramosissimum Michx. ssp. ramosissimum[FNA5, HC2]
bushy knotweed

Publication: Fl. Bor.-Amer. 1: 237. 1803.

Origin: Native

Herbarium search: CPNWH

Notes: FNA5: "Polygonum ramosissimum exhibits considerable morphological complexity and is similar in difficulty to the P. aviculare complex. Further research is necessary to understand the infraspecific variability of this species (M. Costea and F. J. Tardif 2003b).

Subspecies ramosissimum is heterogeneous; some additional elements may deserve recognition. It is closely related to European Polygonum bellardii Allioni, which was collected in south Boston in 1785 (B. L. Robinson 1902). The latter species has semi-open flowers, petaloid tepals with white or pink margins, and eight stamens. A distinct form of P. ramosissimum growing in saline marshes from California has been mistakenly identified as P. patulum Bieberstein (M. Costea and F. J. Tardif 2003b). The morphology of late-season achenes and the branching patterns, which have been emphasized by some authors, appear to have little taxonomic value."

Last updated 2/15/2024 by David Giblin.

Synonyms & Misapplied Names:
Polygonum atlanticum (B.L. Rob.) E.P. Bicknell
Polygonum exsertum Small[HC]
Polygonum interior Brenckle
Polygonum latum Small ex Rydb.
Polygonum leptocarpum B.L. Rob.
Polygonum stevensii Brenckle
Polygonum triangulum E.P. Bicknell